Li joined us on the roof of the barracks for the first time a few days after the half marathon. The sky was turning purple as we climbed the gutter, the sun melting into the horizon like a scoop of orange sherbet dropped on hot asphalt.

We sat on the edge of the roof with our legs dangling into space. Zip squeezed a tennis ball.

“So,” said Li, “is this all you do up here?”

“We talk about stuff,” said Zip.

“Like what?”

“Life. Death. Important stuff.”

“Ah.”

Zip motioned at me. “Sometimes Tetris bitches about Hollywood.”

Li laughed.

“Always plenty to discuss on that front,” I said.

“He’s gotten fast,” said Li. “You saw he finished first in the half marathon?”

“Yeah.”

“Insufferable prick. Cute, though. Especially since I broke his nose. Believe that helped. Gave his face some character.”

My chest tightened. I lay back on the roof, arms crossed behind my head. The sky was full of stars.

“There were never this many stars in Indy,” I said after a while.

Li lowered herself down beside me. On my other side, Zip did the same.

“Space is big,” said Zip.

“Uh huh.”

“The biggest, even.”

One of the stars was moving, blinking across the sky in a steady arc.

“That’s the ISS,” said Li.

We watched it dip beneath the horizon.

“It’ll be back in an hour and a half,” said Li. “It’ll cross all the forests. Europe. Russia. China. Five miles a second. Seventeen thousand miles an hour. You have any idea how fast that is?”

Nobody said anything. It was cold. Li’s arm was pressed against mine. Her skin was soft and warm. Hot, almost. I entertained an urge to inch closer.

“Not fast, actually,” said Li. “Seventeen thousand miles an hour is nothing.”

Zip grunted.

“The solar system itself is moving five hundred thousand miles an hour,” said Li, “as the galaxy spins.”